JP2003240839A - Pulse radar device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem that transmission pulse width as short as 350 ps can not be used under the limit of the existing Radio Law. <P>SOLUTION: This device is equipped with a transmission means 110, a reception means 120, a comparator means 310, a first integration means 420 for sampling received signals at fixed time intervals from the transmission and integrating the results of the sampling at every sampling time for a fixed number of times, a differential operation means 510 for reading the result of integration at the sampling time and operating differentiation in the direction of sampling of the result of integration, a second integration means 520 for integrating the absolute values of output of the differential operation means only for a fixed number of times at every sampling time, a peak detection means 530 for detecting peaks of output of the second integration means, a ranging/ detecting means 540 for calculating distance to an object and determining whether an object exists or not based on an output of the peak detection means, and the like. Even if what is called leak-in signal components exist, the object can be correctly detected. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention transmits radio waves,
The present invention relates to a pulse radar device that detects the presence or absence of an object by receiving a reflected wave of the transmitted radio wave reflected by the object and measures the distance to the detected object.

[0002]

2. Description of the Related Art A conventional pulse radar device will be described with reference to the drawings. FIG. 21 shows, for example, JP-A-7-7.
It is a figure which shows the structure of the conventional pulse radar apparatus shown by 2237 publication.

In this pulse radar device, as shown in FIG. 21, a pulse signal sending means 901 periodically outputs a pulsed signal. Then, the reflected pulse from the object is continuously received by the reflected pulse signal receiving means 903 and binarized by the binarizing means (not shown). Then, after the sending timing of the sending means 901, the sampling means 904 samples the binarized signal for every fixed one or a plurality of sampling points to obtain a sampling value of 0 or 1, and this is sampled for each sampling point. It is given to the addition / storage means 905 corresponding to the point.

Therefore, the adding / storing means 905 adds the sampling value of 0 or 1 by the predetermined number of times of sending of the signal by the sending means 901. When the addition process for the predetermined number of times is completed, the determination unit 906 compares the normalized addition value obtained by dividing the addition value of each addition / storage unit 905 by the number of additions with a predetermined threshold value, and based on the magnitude, external It is determined whether or not there is a reflection signal from the object, and the presence or absence of an external object is determined based on this.

[0005]

[Problems to be Solved by the Invention]
When the reception isolation is poor and there is a so-called leak waveform, or when there is a radome, detection of an object existing at a distance of less than 10 m by using the above-described device and detection of an object up to the object due to the following reasons. It is difficult to measure distance.

That is, in the above conventional apparatus, the transmission pulse width is 66.7 ns, which corresponds to a distance of 10 m. Therefore, as shown in FIG. 22, when an object exists at a distance shorter than 10 m, leakage occurs. A waveform or a waveform in which the reflected wave from the secondary radome and the reflected wave from the object overlap each other is detected. Therefore, the reception level during non-transmission,
If you set the threshold based on the so-called noise level,
There is a problem that only the rising edge of the leak waveform can be detected, and the rising edge of the reflected wave that one really wants to detect cannot be detected.

As a countermeasure against such problems, "W.
Weidmann and D.M. Steinbuc
h, “High Resolution Radar
for Short Range Automoti
ve Applications ”, 28th Eu
ropean Microwave Conferen
Ce Amsterdam, 1998 ”, a method of making the pulse width as short as 350 ps, and a method of canceling a leak waveform by using a transmission waveform as described in JP-A-10-62518. Is proposed.

However, as described in this document, when the transmission pulse width is shortened to 350 ps, the leak waveform and the reflected wave waveform overlap each other only when the distance to the object is about 5 cm or less. However, since the occupied bandwidth becomes extremely wide, there is a problem that it cannot be used within the range of the current Radio Law.

Further, in the case of the method of canceling the leakage waveform by utilizing the transmission waveform as in Japanese Patent Laid-Open No. 10-62518, the difference in time interval between transmission and reception of the leakage waveform due to individual difference or difference in use condition. However, there is a problem in that it is difficult to deal with the difference in the size of the leak waveform and it is necessary to adjust according to the situation.

The present invention has been made to solve the above-mentioned problems, and as shown in FIG. 1, a leak signal between a transmitter and a receiver or a reflection signal from a target fixed to a radar such as a radome, By utilizing the fact that the received signal changes when the phase difference with the reflected signal from the moving target changes, there is a leak signal between the transmitter and the receiver or a reflected signal from the target fixed to the radar such as a radome. Even so, it is an object of the present invention to obtain a pulse radar device capable of correctly detecting an object within the range of the current Radio Law.

[0011]

A pulse radar device according to the present invention comprises transmitting means for transmitting pulsed radio waves, and receiving means for receiving reflected waves in which the radio waves transmitted by the transmitting means are reflected by an object. A comparator means for comparing the received signal from the receiving means with a predetermined level set in advance and binarizing it, and the output of the comparator means is sampled at a predetermined time interval from the transmission, and the sampling result is sampled at every sampling timing. First integration means for integrating a predetermined number of times with each other, differential calculation means for reading the integration result of the first integration means at each sampling timing at predetermined time intervals, and calculating the differentiation of the integration result in the sampling direction, and the differentiation Second integrating means for integrating the absolute value of the output of the computing means a predetermined number of times at each sampling timing; Note Peak detecting means for detecting a peak based on the output of the second integrating means, and distance measuring / detecting means for calculating the distance to the object based on the output of the peak detecting means and determining the presence or absence of the object. And a timing control means for controlling the timing of the transmission, reception, and signal processing of the radio wave.

Further, in the pulse radar device according to the present invention, the differential calculating means outputs the output of the first integrating means at the sampling timing of interest and the output of the first integrating means at the sampling timing adjacent to the sampling timing. The difference is calculated.

Further, in the pulse radar device according to the present invention, the differential operation means outputs the output of the first integrating means at the sampling timing of interest, the sampling timing adjacent to the output, and the sampling timing adjacent to the output. The difference from the output of the integrating means of 1 is obtained, and the sum of them is obtained.

Further, in the pulse radar device according to the present invention, the peak detecting means performs sampling exceeding a preset value among the sampling timings having the maximum in the integration result of the second integrating means at each sampling timing. It outputs the timing.

Further, the pulse radar device according to the present invention further comprises detection threshold value setting means for setting a detection threshold value based on the integration result of the second integration means, and the peak detection means includes Among the sampling timings having the maximum value in the integration result of the second integrating means at the sampling timing, the sampling timing exceeding the detection threshold value set by the detection threshold value setting means is output.

Further, in the pulse radar device according to the present invention, the detection threshold value setting means, in a certain specific sampling timing range, samples the past predetermined number of times of the integration results by the second integration means. An average value is obtained for each timing, the average value is used as a noise level, and at other sampling timings, an average value of the integration results by the second integrating means at one or more sampling timings is obtained,
The average value is used as the noise level, and the detection threshold value is calculated based on the noise level.

Further, in the pulse radar device according to the present invention, the distance measuring / detecting means detects the integration result by the second integrating means at the sampling timing output by the peak detecting means, and the sampling timing before and after the integration result. Of distance calculation means for calculating a distance based on the result of integration by the second integration means, and detection determination means for determining whether or not an object exists based on the calculation result of the distance calculation means. is there.

Further, the pulse radar device according to the present invention further comprises ground level changing means for changing the ground level of the received signal from the receiving means based on the integration result of the first integrating means. .

Further, the pulse radar device according to the present invention obtains an average value of the integration result of each sampling timing by the first integrating means, and changes the ground level when the average value exceeds a predetermined range. It further comprises a ground level control means for outputting the signal to the ground level changing means.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. A pulse radar device according to Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 2 is a diagram showing the configuration of the pulse radar device according to the first embodiment of the present invention. In each figure, the same reference numerals indicate the same or corresponding parts.

In FIG. 2, the pulse radar device according to the first embodiment is roughly composed of five parts.
That is, the RF module 100 and the adder circuit 200
, Comparator circuit 300, and FPGA (field prog
rammable gate array: field programmable gate array) 400 and CPU 500.

Further, in the figure, the RF module 10
0 is a transmission unit 110 that transmits a pulsed electromagnetic wave (center frequency 24.125 GHz) of a predetermined width (for example, 96 ns) at a constant cycle (for example, 1024 ns), and a reception unit for receiving a reflected wave of the electromagnetic wave around an object. Means 12
It consists of 0 and.

Further, in the figure, an adder circuit 200
Is a ground level changing means 210 for changing the ground level based on an instruction from the CPU 500 described later so that the signal received by the receiving means 120 is not saturated.
Have.

Further, in the figure, the comparator circuit 3
00 has comparator means 310 for binarizing the output of the ground level changing means 210.

In the figure, the FPGA 400 is
It is composed of a timing control means 410 and a first integration means 420.

Further, in the figure, the CPU 500 is
The differential calculation means 510, the second integration means 520, the peak detection means 530, the distance measurement / detection means 540 having the distance calculation means 550 and the detection determination means 560, and the ground level control means 570 are realized.

FIG. 3 is a block diagram showing the configuration of the pulse radar device according to the present invention.

In FIG. 3, 110 is a transmitting means for transmitting pulsed radio waves, 120 is a receiving means for receiving the reflected waves of the radio waves transmitted by the transmitting means 110 reflected by a plurality of objects and outputting the received signals, 310 Is the receiving means 120
Comparator means for binarizing the signal from the signal by comparing it with a preset predetermined level, 420 samples the output of the comparator means 310 at a predetermined time interval from transmission, and outputs the sampling result a predetermined number of times at each sampling timing. First integrating means 510 for integrating
Is the first integrating means 4 at each sampling timing
Differentiating means 520 for reading the integration result of 20 at predetermined time intervals and calculating the differentiation of the integration result in the sampling direction.
Is a second integrating means for integrating the absolute value of the output of the differential calculating means 510 a predetermined number of times at each sampling timing,
530 is a peak detecting means for detecting a peak based on the output from the second integrating means 520, and 540 is a distance to the target based on the output from the peak detecting means 530 to determine the presence or absence of the target. Distance measuring / detecting means, 41
Reference numeral 0 is a timing control means for controlling the timing of transmission, reception of radio waves and signal processing.

FIG. 4 is a diagram showing the configuration of the RF module of the pulse radar device according to the first embodiment.

10.8375 by RxLO (150)
The signal of GHz is TxLO in Mixer1 (112).
The signal is mixed with the 1.225 GHz signal by (111), and then a pulse-shaped signal is obtained by the Modulator (113) based on the transmission signal. Next Doubl
er (114) doubles and then Filter1 (1
A signal of 24.125 GHz is generated by 15) and is radiated to the outside as a radio wave from the Tx antenna (130).

The radio wave reflected by an external object is Rx
RxRFAmp (1 is received from the antenna (140).
After being amplified by 21), it is mixed with the signal from RxLO (150) by Mixer2 (122) and dropped to an intermediate frequency. After that, RxIFAmp1
(123), Filter2 (124), RxIFAm
Via p2 (125), Detector (126)
Then, the envelope is detected and becomes the received signal.

FIG. 5 is a diagram showing the configuration of the FPGA of the pulse radar device according to the first embodiment.

In FIG. 5, the FPGA 400 includes a timing control circuit 411, a shift register 421,
Adder 42 corresponding to each bit of shift register 421
2 to 425 and integration registers 426 to 429.

The timing control circuit 411 is the FPGA 4
00 transmitting means 110 based on a clock signal (for example, 125 MHz = 8 ns cycle) by an oscillator connected to the outside.
Is a transmission signal for turning on / off the electromagnetic wave radiation (for example, width 96 ns, cycle 1024 ns), a shift signal for transmitting a bit shift timing to a shift register 421, which will be described later, and addition timings for the adders 422 to 425. Addition signal to be transmitted, accumulation registers 426-4
29 of the addition signal that conveys the timing of holding the outputs of the adders 422 to 425, and CP
An integration process end signal transmitted to U500 is generated.

The shift register 421 stores the binarized data output from the comparator circuit 300 while shifting bit by bit based on the shift signal of the timing control circuit 411. The adders 422 to 425 output 2 of each bit according to the addition signal from the timing control circuit 411.
Quantized data (0 or 1) and integration registers 426 to 42
Add the contents of 9. Accumulation registers 426 to 429
Holds the output from the adders 422 to 425 as integrated data, and outputs the contents of the register when there is a request from the CPU 500.

Next, the operation of this FPGA will be described with reference to FIG. FIG. 6 is a timing chart showing the operation of the FPGA of the pulse radar device according to the first embodiment.

First, based on the external clock signal shown in FIG. 6 (a), the transmission signal shown in FIG. 6 (b) rises and falls 10 clocks later. Simultaneously with the rise of the transmission signal, the shift signal shown in (d) synchronized with the clock signal is output by the number of bits of the shift register 421. Based on this shift signal, the shift register 421 causes the comparator circuit 30
The binary data output by 0 is held in each bit.

Then, after the shift signals for the number of bits of the shift register 421 are output, the addition / integration signal shown in (e) is output. Based on this signal, the adders 422-422
425 and accumulation registers 426 to 429 perform addition and accumulation data retention, respectively. After repeating this operation a predetermined number of times (for example, 1000 times), the CPU 500
In response, the integration processing end signal shown in (f) is output. Upon receiving the integration processing end signal, the CPU 500 reads the contents of the integration registers 426 to 429.

FIG. 7 is a flowchart showing the processing of the CPU of the pulse radar device according to the first embodiment.

First, in step 701, the CPU initializes the inside of the CPU as shown in FIG.

Then, in steps 702 to 703, after initializing the data, the process waits for an integration processing end signal from the FPGA 400.

Next, in step 704, the FPGA
When the integration processing end signal from 400 is received, the integration result at each sampling timing is calculated as FPGA [i] [j].
It will be stored in a two-dimensional array. Where i (= 0 to
N; N is the number of bits of the shift register 421) is the sampling timing, and j (= 0 to 59; second integrating means 5)
(When the number of times of integration at 20 is set to 60) indicates the order of storage.

Next, in steps 705 to 711,
When the number of times the integration processing end signal is received from the FPGA 400 reaches a predetermined number (here, 60 times), ground level control processing (step 706), differential calculation processing (step 707), second integration processing (step 708). , Peak detection processing (step 709), distance calculation processing (step 710), and detection determination processing (step 711).

Thereafter, in step 812, it is confirmed whether or not the processing cycle of 50 ms has elapsed. If it has elapsed, the process returns to step 702 and the same operation is repeated.

The ground level control process will be described in more detail.

FIG. 8 is a diagram for explaining the ground level control. Further, FIG. 9 shows the first embodiment.
5 is a flowchart showing the operation of a ground level control process in the CPU of the pulse radar device according to the present invention.

As shown in FIG. 8, when a threshold value is set at the position A in the figure and binarization is performed, the value is always 1 and the object cannot be detected regardless of the presence or absence of the surrounding object. The ground level control process is a process for adjusting the ground level of the received signal to raise or lower the entire received signal so that the threshold value comes to the position B in the figure.

In steps 901 to 908, the sum Su of the integrated values of 60 times at each sampling timing is Su.
Find m [i].

Next, at step 909, the average value SumMean of the sum Sum [i] of the integrated values at each sampling timing is calculated at.

Next, in steps 910 to 914,
SumMean and preset value SUMMEAN
When 1 is compared and SUMMEAN1 is smaller, the instruction value (control value) to the adder circuit 200 which is the ground level changing means 210 is decreased in step 912. on the other hand,
If SUMMEAN1 is larger, step 911.
In SumMean2 and SUMMEAN2 (however, SUM
Compare MEAN1> SUMMEAN2), and
When EAN2 is larger, the instruction value (control value) to the adder circuit 200 which is the ground level changing means 210 is increased in step 914. If SUMMEAN2 is smaller, the previous instruction value (control value) is held as it is in step 913.

Then, in step 915, the instruction value (control value) is D / A converted and output from the CPU 500.
The ground level of the received signal is adjusted by adding the received signal in the adder circuit 200. In addition, the first embodiment
Then, the threshold value position is adjusted by changing the ground level of the received signal, but the threshold value itself may be controlled.

Next, the differential operation processing (step 707),
The second integration process (step 708) will be described in detail.

10 and 11 are diagrams for explaining the differential operation processing in the CPU of the pulse radar device according to the first embodiment. Further, FIG. 12 is a diagram for explaining the second integration processing in the CPU of the pulse radar device according to the first embodiment.

FIG. 13 is a flow chart showing the operation of the differential operation processing in the CPU of the pulse radar device according to the first embodiment. Further, FIG. 14 shows the first embodiment.
2 is a flowchart showing the operation of a second integration process in the CPU of the pulse radar device.

When the relative distance between the peripheral object and the radar is changing, as shown in FIG. 1, the sampling timing corresponding to the portion where the leak-in signal component and the reflection signal component from the peripheral object are superimposed. Then, the magnitude of the signal changes. Therefore, the integration data (first integration process) from the FPGA 400 is differentiated in the sampling direction.

That is, when the difference between the integrated data at the sampling timing of interest and the integrated data at the sampling timing adjacent thereto is calculated, if the leak-in signal component and the reflection signal component from the surrounding object are strengthened,
It becomes like FIG.

On the other hand, when the leak-in signal component and the reflection signal component from the surrounding object weaken each other, the result is as shown in FIG. Therefore, when the relative distance between the peripheral object and the radar changes, the differential value changes from plus to minus and from minus to plus.

Therefore, if the absolute values of the differential values are summed up, the result becomes as shown in FIG. 12. Therefore, the peak is obtained from this, and the peripheral object is detected by comparing it with a preset threshold value.

Here, the first peak is due to the rising edge of the received waveform. In the short-distance range affected by this rising edge, by setting the threshold value higher than that, the short-distance influences the rising edge. Peripheral objects can also be detected for the range.

In order to realize the above, first, in the differential operation process of step 707, the process shown in the flowchart of FIG. 13 is performed to calculate the differential value at each sampling timing.

Further, in the second integration processing of step 708, the processing shown in the flowchart of FIG.
The absolute value of the differential value at each sampling timing is integrated.

Further, in the peak detection processing of step 709, the processing shown in the flowchart of FIG.
Using the output of the above-mentioned second integration processing, the sampling timing at which the maximum is reached is obtained. Among them, the detection threshold ThS for each preset sampling timing
Sampling timing Peak exceeding um [i]
[PeakNo] is output.

In the following distance calculation processing of step 710,
The process shown in the flowchart of FIG. 16 is performed to calculate the distance.

That is, first, in step 1601, it is determined whether or not the PeakNo calculated in the peak detection process is 0. If this PeakNo is 0, it means that there is no peak exceeding the preset value, and therefore the detection distance DetDist is determined in step 1612.
[0], DetDist [1] to the maximum distance DETDIS
T_MAX.

On the other hand, if PeakNo is greater than 0, then in step 1602 the first peak Peak is reached.
Second at the sampling timings on both sides of k [0]
The integrated values are compared, and when the second integrated value at the sampling timing on the left side is larger than the second integrated value on the right side, the process proceeds to step 1603.

In Step 1603, Peak
[0], Peak [0] -2, Peak [0]-
The second integrated value at the sampling timing of 1, Peak [0] +1 is used, and the weighted average is calculated.

If the second integrated value at the sampling timing on the left side is smaller than the second integrated value on the right side, the process proceeds to step 1604, where Peak [0] and
Peak [0] -1, Peak [0] +1, Peak
The second integrated value at the sampling timing of [0] +2 is used and the weighted average is calculated.

Next, in step 1605, the distance DIST_UNIT corresponding to one sampling is multiplied, and 256 is multiplied to obtain the unit [m / 256].

Next, in step 1606, another
It is determined whether or not one peak exists, and if there is one peak, the process proceeds to step 1607 and the same processing as above is performed.
If the second peak does not exist, DetDist
Let [1] be the maximum distance DETDIST_MAX. It should be noted that the case where two peaks are obtained is shown here, but the process is the same when more peaks are obtained.

Further, in the detection determination processing of step 711, by performing the counter processing as shown in the flowchart of FIG. 17, the detection flag is set only when the detection distance is calculated to some extent stable, and Prevents false detection due to noise.

As described above, according to the first embodiment, the change start point of the signal magnitude at each sampling timing generated by the phase difference between the leak signal component and the reflected signal component is detected by differentiation. Since the absolute value is integrated and detected to calculate the distance to surrounding objects, there is a so-called leak signal component such as a leak signal between the transmitter and receiver or a reflection signal from a target fixed to the radar such as a radome. However, the object can be detected correctly.

Further, by using the second integrated value at the sampling timing which becomes the peak and the second integrated values at the sampling timings before and after it (weighted average)
Since the distance is calculated by interpolation, the resolution of distance measurement can be improved even with a rough sampling interval.

Further, by adjusting the ground level according to the magnitude of the received signal as a whole, the threshold value for binarization is automatically set to an appropriate place, so that the mounting state is different. Even if the leak signal components are different, it can be used without any special adjustment or modification to the radar.

Embodiment 2. A pulse radar device according to Embodiment 2 of the present invention will be described with reference to the drawings. FIG. 18 is a flowchart showing the processing of the CPU of the pulse radar device according to the second embodiment of the present invention.

The second embodiment is a modification of the processing in the CPU 500 according to the first embodiment, and the other parts, that is, the RF module 100, the adder circuit 200, the comparator circuit 300, and the FPGA 400.
The contents of are the same as those of the first embodiment. The outline of the processing is shown in FIG.

As shown in FIG. 18, first, step 18
At 01, the inside of the CPU 500 is initialized.

Subsequently, in step 1802, after initializing the data, in step 1803 the FPGA 4
Wait for the integration processing end signal from 00.

When the integration processing end signal from the FPGA 400 is received, in step 1804, the integration result at each sampling timing is stored in the two-dimensional array FPGA [i] [j]. Where i (= 0 to N;
N is the number of bits of the shift register 421) is the sampling timing, j (= 0 to 59; second integrating means 520)
(When the number of times of integration in 60 is set) indicates the order of storage.

In step 1805, the FPGA 40
When the number of receptions of the integration processing end signal from 0 reaches a predetermined number (here, 60 times), the processing from step 1806, that is, the ground level control processing (step 18).
06), differential calculation processing (step 1807), second integration processing (step 1808), detection threshold value setting processing (step 1809), peak detection processing (step 18).
10), distance calculation processing (step 1811), and detection determination processing (step 1812).

Thereafter, in step 1813, it is confirmed whether or not the processing cycle of 50 ms has elapsed, and if it has elapsed, the process returns to step 1802 and the same operation is repeated.

The differential calculation process (step 1807), which is a process different from that of the first embodiment, will be described below.

In this differential operation processing (step 1807), the integrated data from the FPGA 400 (first integrated processing) is differentiated in the sampling direction.

That is, the difference between the integrated data at the sampling timing of interest and the integrated data at the adjacent sampling timing, and the difference between the integrated data at the sampling timing of interest and the integrated data at the adjacent sampling timings, are obtained, respectively. Calculate the sum of By doing so, the signal level with respect to the noise level, that is, the S / N can be improved. In order to realize the above calculation, in the differential calculation process, the process is performed as shown in the flowchart of FIG. 19, and the differential value at each sampling timing is calculated.

Next, the detection threshold value setting process (step 1
809) and peak detection processing (step 1810) will be described.

The detection threshold value setting process and the peak detection process correspond to the peak detection process in the first embodiment, and are automatically performed even when the environment in which the radar is used changes and the noise level changes. It is for learning it so that it can be used without any special changes.

The detection threshold value setting process will be described.
In this process, as shown in FIG.
1, the differential integrated value (second integration processing output) Sum
Average value AveSu of [i] (however, i = M1 to M2)
Find m. As for M1 and M2, a range that is not affected by the rising of the received signal (a very short distance) and a range in which no normal object is present are selected. Further, M1 = M2, and the change integrated value at any one sampling timing may be used as it is as AveSum.

Next, in step 2002, a predetermined value is added to the average value AveSum to detect the detection threshold ThSum.
Let Val [i] (i = 0 to M). The amount to be added may be set in advance based on the noise level variation, or the average value AveSum and the differential integrated value Sum may be set.
The maximum value of the variation with [i] may be calculated and set using that value.

Next, in step 2003, the average value for each sampling timing in the past Z times is calculated in the range M3 to M4 affected by the rising of the received signal, and is set as AveSum2 [i].

Next, in step 2004, a predetermined value is added to the average value AveSum2 [i], and the detection threshold value T
Let hSumVal [i] (i = M3 to M4).

The peak detection processing in step 1810 in FIG. 18 is performed by ThSum in step 1508 in FIG.
Processing in which [i] is changed to ThSumVal [i] is performed.

As described above, according to the second embodiment, by taking the difference between the sampling timing of interest and the integrated value at the adjacent sampling timings and taking the sum as the differential value, the noise level with respect to the noise level can be obtained. The signal level, that is, the S / N can be improved.

Further, since the threshold value for the differential integrated value is changed according to the fluctuation of the noise level, even if the same radar is used and the noise level is increased / decreased due to movement of the use place or the like, the radar level is changed. Can be used without any special adjustments or changes to.

[0093]

As described above, the pulse radar device according to the present invention comprises the transmitting means for transmitting the pulsed radio wave and the receiving means for receiving the reflected wave reflected from the object by the radio wave transmitted by the transmitting means. , Comparing the received signal from the receiving means with a predetermined level set in advance, 2
The comparator means for digitizing, the first integrating means for sampling the output of the comparator means at a predetermined time interval from transmission, and integrating the sampling result a predetermined number of times at each sampling timing, and the first integrating means at each sampling timing. 1) The integration result of the integration unit 1 is read out every predetermined time, and the differential operation means for calculating the differential of the integration result in the sampling direction, and the absolute value of the output of the differential operation means are integrated for a predetermined number of times at each sampling timing. No. 2 integrating means, peak detecting means for detecting a peak based on the output of the second integrating means, and a distance to the object based on the output of the peak detecting means to determine the presence or absence of the object. And a timing control means for performing timing control of transmission and reception of the radio wave and signal processing. Since with the door, even in the presence of a so-called leak signal component, an effect that incorrect object can detect.

Further, in the pulse radar device according to the present invention, as described above, the differential operation means outputs the output of the first integrating means at the sampling timing of interest and the first output at the sampling timing adjacent thereto. Since the difference from the output of the integrating means is obtained, there is an effect that an object can be correctly detected even if a so-called leak signal component exists.

In the pulse radar device according to the present invention, as described above, the differential operation means outputs the output of the first integrating means at the sampling timing of interest, the sampling timing adjacent to the output, and the adjacent sampling timing. Since the difference from the output of the first integrating means at the sampling timing is obtained and the sum thereof is obtained, the S / N can be improved.

Further, in the pulse radar device according to the present invention, as described above, the peak detecting means sets in advance the sampling timing which becomes maximum in the integration result of the second integrating means at each sampling timing. Since the sampling timing exceeding the above value is output, there is an effect that an object can be correctly detected even if a so-called leak signal component exists.

Further, as described above, the pulse radar device according to the present invention further comprises the detection threshold value setting means for setting the detection threshold value based on the integration result of the second integration means, The detecting means determines, among the sampling timings having the maximum value in the integration result of the second integrating means at each sampling timing,
Since the sampling timing exceeding the detection threshold value set by the detection threshold value setting means is output, even if the same radar is used and the noise level is increased or decreased under different use conditions due to movement of the use place, the radar There is an effect that it can be used without special adjustment or change.

Further, in the pulse radar device according to the present invention, as described above, the detection threshold value setting means uses the second integrating means for a predetermined number of times in the past within a specific sampling timing range. Regarding the integration result, an average value is obtained for each sampling timing, and the average value is used as a noise level. At other sampling timings, the average value of the integration results by the second integrating means at one or a plurality of sampling timings is set. Obtained, the average value as the noise level, because the detection threshold value is calculated based on the noise level, even if the noise level increases or decreases due to different operating conditions due to movement of the operating location even with the same radar, Can be used without any special adjustment or modification to the radar The effect say.

Further, in the pulse radar device according to the present invention, as described above, the distance measuring / detecting means outputs the integration result by the second integrating means at the sampling timing output by the peak detecting means, and Distance calculating means for calculating a distance based on the integration result of the second integrating means at the front and rear sampling timings, and detection determining means for determining whether or not an object exists based on the calculation result of the distance calculating means. Since it has, it is possible to improve the resolution of the distance measurement even with a rough sampling interval.

Further, as described above, the pulse radar device according to the present invention further includes ground level changing means for changing the ground level of the received signal from the receiving means based on the integration result of the first integrating means. Since it is provided, even if the mounting state is different and the leak signal component is different, it is possible to use the radar without any special adjustment or change.

Further, as described above, the pulse radar device according to the present invention obtains the average value of the integration result for each sampling timing by the first integrating means, and when this average value exceeds the predetermined range. , Further comprising ground level control means for outputting a signal for changing the ground level to the ground level changing means, so that even if the mounting state is different and the leak signal component is different, special adjustment or change is made to the radar. There is an effect that it can be used without any.

[Brief description of drawings]

FIG. 1 is a diagram for explaining that a received signal changes due to a change in phase difference of a pulse radar device according to the present invention.

FIG. 2 is a diagram showing a configuration of a pulse radar device according to the first embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of a pulse radar device according to the first embodiment of the present invention.

FIG. 4 is a diagram showing a configuration of an RF module of the pulse radar device according to the first embodiment of the present invention.

FIG. 5 is a diagram showing a configuration of an FPGA of the pulse radar device according to the first embodiment of the present invention.

FIG. 6 is a flowchart showing the operation of the FPGA of the pulse radar device according to the first embodiment of the present invention.

FIG. 7 is a flowchart showing the operation of the CPU of the pulse radar device according to the first embodiment of the present invention.

FIG. 8 is a diagram showing a ground level control operation of the CPU of the pulse radar device according to the first embodiment of the present invention.

FIG. 9 is a flowchart showing a ground level control process of the pulse radar device according to the first embodiment of the present invention.

FIG. 10 is a diagram for explaining a differential calculation process of the pulse radar device according to the first embodiment of the present invention.

FIG. 11 is a diagram for explaining a differential calculation process of the pulse radar device according to the first embodiment of the present invention.

FIG. 12 is a diagram for explaining a second integration process of the pulse radar device according to the first embodiment of the present invention.

FIG. 13 is a flowchart showing a differential calculation process of the pulse radar device according to the first embodiment of the present invention.

FIG. 14 is a flowchart showing a second integration process of the pulse radar device according to the first embodiment of the present invention.

FIG. 15 is a flowchart showing peak detection processing of the pulse radar device according to the first embodiment of the present invention.

FIG. 16 is a flowchart showing a distance calculation process of the pulse radar device according to the first embodiment of the present invention.

FIG. 17 is a flowchart showing a detection determination process of the pulse radar device according to the first embodiment of the present invention.

FIG. 18 is a flowchart showing the operation of the CPU of the pulse radar device according to the second embodiment of the present invention.

FIG. 19 is a flowchart showing a differential calculation process of the pulse radar device according to the second embodiment of the present invention.

FIG. 20 is a flowchart showing a detection threshold value setting process of the pulse radar device according to the second embodiment of the present invention.

FIG. 21 is a block diagram showing a configuration of a conventional pulse radar device.

FIG. 22 is a diagram for explaining a leak wave and a reflected wave of the conventional pulse radar device.

[Explanation of symbols]

100 RF module, 110 transmitting means, 120
Receiving means, 200 adder circuit, 210 ground level changing means, 300 comparator circuit, 310 comparator means, 400 FPGA, 410 timing control means, 420 first integrating means, 500 CPU,
510 differential calculating means, 520 second integrating means, 53
0 peak detecting means, 540 distance measuring / detecting means, 550
Distance calculation means, 560 detection determination means, 570 ground level control means.

Claims (9)

[Claims] 1. A transmitting means for transmitting a pulsed radio wave, a receiving means for receiving a reflected wave of the radio wave transmitted by the transmitting means reflected by an object, and a predetermined signal preset with a received signal from the receiving means. Comparator means for binarizing in comparison with the level; first integrating means for sampling the output of the comparator means at a predetermined time interval from transmission and integrating the sampling result a predetermined number of times at each sampling timing; Differentiating operation means for reading out the integration result of the first integrating means at each sampling timing at every predetermined time and calculating the differentiation of the integration result in the sampling direction, and sampling the absolute value of the output of the differentiation operation means a predetermined number of times. Second accumulating means for accumulating at each timing, and peak detection based on the output of the second accumulating means Peak detecting means, distance measuring / detecting means for calculating the distance to the object based on the output of the peak detecting means, and determining the presence / absence of the object, timing of transmission, reception, and signal processing of the radio wave A pulse radar device comprising: a timing control means for controlling. 2. The output of the first integrating means at a sampling timing of interest, the differential calculating means,
2. The difference between the output of the first accumulating means at the sampling timing adjacent thereto is calculated.
The pulse radar device described. 3. The differential calculating means, and the output of the first integrating means at the sampling timing of interest,
2. The pulse radar device according to claim 1, wherein the difference between the adjacent sampling timing and the output of the first integrating means at each adjacent sampling timing is obtained, and the sum thereof is obtained. 4. The peak detection means outputs a sampling timing that exceeds a preset value among the sampling timings having the maximum in the integration result of the second integration means at each sampling timing. The pulse radar device according to claim 1, 2 or 3. 5. A detection threshold value setting means for setting a detection threshold value on the basis of the integration result of the second integration means, wherein the peak detection means is the second integration means at each sampling timing. Among the sampling timings having the maximum value in the integration result of, the sampling timing exceeding the detection threshold value set by the detection threshold value setting means is output.
The pulse radar device according to 2 or 3. 6. The detection threshold value setting means, in a certain specific sampling timing range, about a predetermined number of past past integration results by the second integration means,
An average value is calculated for each sampling timing, and the average value is used as a noise level. At other sampling timings, an average value of the integration results by the second integrating means at one or more sampling timings is calculated, and the average value is calculated. The pulse radar device according to claim 5, wherein the value is a noise level, and the detection threshold value is calculated based on the noise level. 7. The distance measuring / detecting means integrates the result of integration by the second integrating means at the sampling timing output by the peak detecting means and the integrating result by the second integrating means at sampling timings before and after the integration result. 6. A distance calculation unit that calculates a distance based on the result, and a detection determination unit that determines whether or not an object exists based on the calculation result of the distance calculation unit. 6-pulse radar device. 8. The method according to claim 1, further comprising ground level changing means for changing a ground level of a reception signal from the receiving means based on an integration result of the first integrating means. The pulse radar device according to any one of 1 to 3 above. 9. An average value of integration results of each sampling timing by the first integration means is obtained, and when the average value exceeds a predetermined range, a signal for changing the ground level is sent to the ground level changing means. 9. The pulse radar device according to claim 8, further comprising ground level control means for outputting.